<!DOCTYPE html>
<html>
	<body>
		<style>
a:lang(en) {--lang: 'en';}
a:lang(de) {--lang: 'de';}
a { test: var(--lang); }
		</style>

		<a lang="en" data-ruleset="test: 'en';">link</a>

		<a lang="de" data-ruleset="test: 'de';">link</a>

	</body>
</html>
